Handheld electronic devices, such as cellular telephones, are routinely carried and used by large segments of the population. Many people today would not think of leaving home without their mobile phone, whether they are departing for work, leaving on a vacation, venturing out to shop about town, departing for dinner or a movie, or just enjoying a relaxing stroll around the neighborhood. As cellular carriers have expanded network coverage to include an ever-increasing national and international calling area, cellular telephones have become ubiquitous communications facilitators for everyone from businesspeople to students. Similarly, advances in technology have enabled cell phone manufacturers to reduce the size of mobile phones and offer improved form factors, thereby fueling the devices' popularity. Technology advances have also made possible the inclusion of features beyond the original voice communications. For example, text messaging capability is now common on mobile phones, as is the capability to access the Internet. A recent advance involves integrating a digital camera within the mobile phone. Using a camera-equipped phone, a user can capture an image using the digital camera, store the image in memory, upload the image to a remote storage location via a network, or transmit the image to another user.
It is known to use mobile phones to obtain location-based information. For instance, some mobile phones include global positioning system (GPS) functionality, which can be used determine a location via communication with GPS satellites. Users of GPS-equipped phones may typically subscribe to a GPS navigation service through their cellular provider. However, GPS functionality on mobile devices may be expensive, and may be difficult to use. Additionally, because satellite communication is required to determine a location using GPS, and because GPS satellites orbit the earth in prescribed orbital planes, use of GPS on a mobile device may require an unobstructed view of a particular region of the sky to facilitate such communication. This may be problematic in areas where unobstructed skyward views are in short supply or not available at all. For example, GPS functionality may not be possible in dense metropolitan areas where large buildings block direct skyward views of the GPS satellite orbital paths. Also, some people have privacy concerns with GPS technology, and may not wish to carry a device that may permit precise tracking without their consent.